PEP 0007: Only use C++ style // one-line comments

[DimitriPapadopoulos]

PEP 0007 itself states:

Only use C++ style // one-line comments in Python 3.6 or later.

Therefore switch to C++ style // one-line comments.

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[DimitriPapadopoulos]

I did sign the CLA - minutes before creating the PR.

[zware]

There is a human review step to the CLA process, so it will take some time before @the-knights-who-say-ni recognizes that you have signed.

As far as the content of the PR, I think you may be mistaking the point of that line: it is not saying that only C++-style one-line comments should be used, but that such comments should not be used in versions of Python before 3.6. There is no prohibition against single-line multi-line-style comments.

[DimitriPapadopoulos]

Ah right, got it. I'm not a native speaker, but I think the text can be interpreted both ways:

1. Do not use C++ style // one-line comments before Python 3.6.
2. Use only C++ style // one-line comments starting with Python 3.6.

Of course, the first interpretation is the most straightforward and obvious, and the second one is convoluted. Still, to accommodate non-native speakers, I would recommend changing to something like this:
Do not use C++ style // one-line comments before Python 3.6.

Much easier to understand, at least for me.

[Rosuav]

Since Python 3.6 is now the oldest version still supported, perhaps it can be worded more positively, as a permission rather than a version-specific prohibition? "As of Python 3.6, C++ style // one-line comments may be used freely."

[warsaw]

I'm of the mind that since 3.5 is EOL'd we can just remove the Python version qualifier.

[DimitriPapadopoulos]

I'm of the mind that since 3.5 is EOL'd we can just remove the Python version qualifier.

If so, this sentence can be removed altogether 😄

[DimitriPapadopoulos]

Since Python 3.6 is now the oldest version still supported, perhaps it can be worded more positively, as a permission rather than a version-specific prohibition? "As of Python 3.6, C++ style // one-line comments may be used freely."

Or something like this, whatever you prefer.
As of Python 3.6, both C++ style // and C89 style /**/ can be used for one-line comments.

Is there a preferred style for longer comments, by the way? Why refer to one-line comments?

But again, perhaps this sentence should be removed if Python 3.5 is EOL'd. Actually, I have found 3 occurrences of references to versions of Python < 3.6, the last one being the worst offender!

• Python versions before 3.6 use ANSI/ISO standard C (the 1989 version of the standard).
• Python versions greater than or equal to 3.6 use C89 with several select C99 features:
• For C code that needs to support versions of Python older than 2.3, you can include this after including Python.h:

[gvanrossum]

I'm not really interested in this discussion, except to confirm that the OP misunderstood the intention, and the PR as it stands should not be accepted.

[DimitriPapadopoulos]

I would be interested to know why you think I misunderstood the intention. Is it because I am not a native speaker, or because the wording truly is ambiguous?

[zware]

It may very well be ambiguous; I'm having a hard time seeing it that way, but I'm also more familiar with the history here. I would support removing the Only use ... line and cleaning up the 2.3 reference in a new PR, but there's no need to change the comments throughout the file.

[Rosuav]

It may very well be ambiguous, but I believe Guido's point is that this particular PR shouldn't be accepted. Feel free to open a separate PR changing the wording of that comment.